Contact member for electronic tubes



Jan. 16, 1951 w. w. WATROUS, JR

CONTACT MEMBER FOR ELECTRONIC TUBES Filed Feb. 19, 1949 INVENTOR 14 h h flffflmifr.

ATTORNEY Patented Jan. 16, 1951 CONTACT MEMBER FOR ELECTRONIC TUBES Ward W. Watrous, Jn, Chatham, N. J., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 19, 1949, Serial No. 77,328 5 Claims. (01. 250-215) 1 This invention relates to electronic tubes and other electrical devices, and especially to the metal cap often used with such devices, as an exterior contact element on the device envelope provided in addition to the usual lead-in contacts through the base. While the invention has been arbitrarily shown at an end of the device envelope directly opposite from the base, its location may be at any other part of the envelope where desired to position the same for lead-in or other purpose. I

While the conventional method of forming such a connection hasusually been to solder the lead wire to the inside'of the cap, I have shown in my prior Patent 2,325,817 of August 3, 1943, a cap wherein the lead wire could be extended through the cap and soldered from the outside. That structure had pronounced advantages over the prior art, and the present invention proposes additional improvement thereover.

One object of the present invention is to overcome necessity for use of a reentrant type of cap.

' Another object of the invention is to lessen the danger of cracking the glassor other envelope material around the lead-in wire either during fabrication or during use of the device. 1

A further object of the invention is to provide a structure wherein the lead-in wire may be welded to the cap in full view of the operator making the weld.

An important object of the invention'is to provide a cap of the character indicated which avoids projections from the outer cap surface.

A still further object of the invention i to increase the tolerance in location of the cap in cementing or otherwise attaching the cap to the envelope.

Yet another object of the invention is to simplify the glass or container construction for the lead-in seal and for the mounting of the cap,

Fig. 1 is a side elevation of an electronic tube v having the present invention incorporated there with;

Fig. 2 is a perspective view of the cap of the present invention;

Fig. 3 is a sectional view of a portion of the electronic tube with the present invention applied in partially completed fabrication of the assembly; and

Fig. 4 is a view of a corresponding portion of the tube in elevation and with the present invention applied in its completed assembly and with the'cap partially in section.

In the specific embodiment of the novel concept illustrated in said drawing, an electronic device, specifically a thyratron, has been arbitrarily selected with which to apply the present invention, but is to be understood at the outset that other specific constructions and types of electronic devices may equally Well incorporate the innovation. The chosen device shown comprises a glass or other suitable vacuum-tight envelope it] provided with a reentrant stem H at one end, which for orienting purposes ,will be referred to herein as the bottom or lower end of the device, and through said stem are sealed lead-in wires l2 for making connection to exterior terminal prongs l3 projecting from the bottom of a base I4 carried by the lower end of the envelope. Within the envelope the lead-in wires make appropriate connection to certain electrodes, such as to a cathode l5 and grid l6. Within and near the top of the envelope is another electrode, specifically an anode l1, audit is for purposes of providing an improved lead-in connection for this electrode that constitutes the basis of the present invention.

7 As shown, the glass of the envelope I0 is sealed around a suitable rigid lead-in post l8 which extends at one end into the envelope adequatel for rigid attachment of the anode thereto, and extends at its other end to the exterior of the envelope and there'is provided with afiexible leadin connection or wire I9 constituting an integral extension of said post. This flexible lead-in connection may conveniently comprise stranded copper wire for maximum flexibility and minimum resiliency, and is shown bent into a close loop {9a giving to the connection appearance suggestive of a pigtail by which name said connection may be identified herein. Thi construction enables the anode to be rigidly and accurately mounted but provides a flexible pigtail the outer end of which can be attached to a metallic terminal cap 2!] without need of careful alignment or fear of cracking the seal.

The terminal cap 20 comprises essentially a cylindrical neck portion 2i merging at its lower end into a flaring shoulder 22 which is bounded peripherally by a depending cylindrical flange 23. The terminal cap is applied to the end of 3 the envelope with the lead-in wire and pigtail projecting into the cylindrical neck portion thereof and with the cap substantially coaxial with the lead-in post i 8. Suitable cement 24 included between the cap shoulder and the envelope retains said cap in its assembled position.

The extreme end of neck portion 2i of the ter minal cap away from the shoulder is provided with a transverse end wall 25 from which a tab 26 is struck thereby providing an aperture 2! of the same shape as the tab and with the tab integral, at one side of the aperture, with the main body of the end wall. Preferably in striking up said tab, it is bent outwardly substantially perpendicular to the end wall. The size of the aperture is made large enough to freely pass the end of the pigtail therethrough.

In fabrication and assembly, the envelope I8 is completed and provides the above-described rigid anode post it and pigtail flexible extension i9 thereof projecting at the top of the envelope. The cap 28 is then applied on and cemented to the end of the envelope, care being taken in applying the cap to feed the projecting end of the pigtail through said aperture 2? so it will project in the vicinity of the upstanding tab 26; The said projecting end of the pigtail which, with the tab, is readily accessible to an operator and welding machine, is then spot welded to the face of the tab after which the tab is bent down t again lie in the plane of the end wall 25 of the cap entirely enclosing the lead-in wire or pigtail. The completed structure accordingly avoids any pro- .jection of tab or lead-in wire and presents to ex-- terior view only a symmetrical cap with cylindrical neck and plane closed end, as shown in Figs. 1 and 4. It may be added, that by applying the cap as shown in the drawing so the tab is at the opposite side of the pigtail from the ioop, the operation of closing the tab into the aperture flexes the pigtail at the loop without applying any descriptive strain upon the rigid post or glass seal.

I claim:

1. A contact member for a lead-in connection to an electric device, comprising a cylindrical portion and a transverse wail across an extreme end of said cylindrical portion, said transverse wall having a substantially planar surface and having an aperture, and a tab corresponding in size and shape to said aperture and said tab ha"- ing two faces opposed on opposite sides of said tab, said tab being bendable at an edge of said faces into said aperture for locating one of said faces substantially in the plane of the outer surface of said transverse wall and for directing the other of said faces inwardly of the said cylindrical portion.

2. A contact member for a lead-in connection to an electric device, comprising a cylindrical por- 4 of said faces inwardly of the said cylindrical portion and a lead-in wire attached to the inwardly directed face of said tab.

3. A contact member for a lead-in connection to an electric device, comprising a cylindrical portion and a transverse wall across an extreme end of said cylindrical portion, said transverse wall having a substantially planar surface and having an aperture, and a tab corresponding in size and shape to said aperture and said tab having two faces opposed on opposite sides of said tab, said tab being bendable at an edge of said faces into said aperture for locating one of said faces substantially in the plane of the outer surface of said transverse Wall and for directing the other of said faces inwardly of the said cylindrical portion and a flexible lead-in wire attached to the inwardly directed face of said tab, said flexible wire extending transverse to said bendable edge of the tab and ending next a part of said face remote from the said bendablev edge of the tab.

4. A contact member for a lead-in connection to an electric device, comprising a cylindrical portion and a transverse wall across an extreme end of said cylindrical portion, said transverse wall having a substantially planar surface and having a tab with two faces opposed on opposite sides of said tab, said tab being bendable at an edge of said faces for locating one of said faces substantially in the plane of the outer surface of said transverse wall and for directing the other of said faces inwardly of the said cylindrical portion and a flexible lead-in wire attached to the inwardly directed face of said tab, said flexible wire extending transverse to said bend-able edge of the tab and ending next a part of said face remote from said bendable edge of the tab and the said flexible wire having a portion extending past the said bendable edge of the tab away from the tab and therebeyond having a pig-tail curl looping first toward the said attached end of the lead-in wire and away fro-m said bendable edge of the tab and then toward the bendable edge and finally back to its original direction of projection from the tab whereby the pig-tail curl permits bending the tab and yet bending the tab to its position substantially in the plane of the transverse wall tends to tighten the pig-tail curl of said flexible lead-in wire.

5. A contact assembly comprising a glass envelope, a rigid post sealed through a wall of said envelope providing an outwardly projecting post end, a flexible pigtail extension on said outwardly projecting post'end, a cap enclosing said pigtail extension, and a tab integral with said cap and welded to said pigtail extension.

WARD W. WATROUS, J R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date- 1,965,338 Gibson Jul 3, 1934 1,969,496 Beardow Aug. 7, 1934 2,084,734 Krahl June 22, 1937 2,359,769 Litton Oct. 10, 1944 

